2 56 THE DISPERSAL OF SHELLS. 



[Helix aperta Born, another Mediterranean species, 

 hardly ought to be mentioned here at all, for it has 

 never been found, as far as I know, either living or 

 dead, in any of the islands of the British archipelago ; 

 it was introduced into our fauna, however, in 1839, when 

 a specimen received from Forbes, as from Guernsey, is 

 said to have been placed in the British Museum by 

 Gray ; but Guernsey, of course^ belongs geographically 

 to France. The species was included by Gray in the 

 '^Turton" of 1840, where it is stated that the shell, 

 which was a crushed specimen, was found in mud under 

 the side of a hedge, a situation similar to those in which 

 Forbes had found the snail in Provence; and Forbes 

 and Hanley included it in their celebrated work of 1853 ; 

 but, in the " Turton '^ of 1 857, Gray excluded it, believing 

 that it had been previously included by mistake. Jeffreys 

 (1862) remarked upon the fact that the sole ground for 

 supposing the species to be a native was the discovery 

 of the shell above mentioned (which he described as a 

 dead specimen found in a cart-track), adding that Dr. 

 Lukis, then and at the time of the discovery a resident 

 in Guernsey, had frequently searched for the shell in 

 vain ; its shape, he significantly remarked, " is not much 

 unlike that of the variety tenuis of Helix aspersa which 

 is common in Guernsey and is frequently bandless 

 and without coloured markings." He also stated 

 that Forbes' shell could not be found for reference 

 in the British Museum, Dr. Baird (then in charge 

 of the shells) never having seen it. Quite possibly, 

 of course, as Jeffreys admitted, the shell in question 



